Njst need answers to these

QUESTION 16 A sample are asked their gender, and to compare their internet shopping patterns in the last six months to a similar period one year ago. The resulting contingency table is: Less now Same now More now Male 12 35 20 Female 9 29 14 Assuming gender and spending are independent, what is the expected frequency of males who spend the same now (to 1 decimal place)? Note that n = 119 QUESTION 14 You wish to test the null hypothesis H0: p = 0.15 using a sample with sample proportion = 0.21 and n = 50. What is the value of the test statistic? (Write your answer to 2 decimal places) NB: the sample proportion has standard error P(1-P) n QUESTION 15 In a sample of 50 BA students, 16 take the train everyday, while in a sample of 45 BCom students, 5 take the train everyday. What is the pooled sample proportion of students who take the train everyday? (Give your answer to 2 decimal places.) QUESTION 12 A random sample of rms contains 26 with at least 50 employees, and 43 with fewer than 50 employees. What is the sample proportion of firms with fewer than 50 employees? (Give your answer to 2dp) QUESTION 13 A researcher wishes to estimate a population proportion to within a margin of error of 0.08. A pilot sample of 75 observations has a sample proportion equal to 0.8. Using this sample proportion, how large a sample is needed to achieve the desired margin of error? _ 2 NB: the solution tom = 1.961! g isn = [%) p(1 p) QUESTION 8 A sample from a normally distributed population yields the following statistics: sample mean = 32.8, sample standard deviation = 4.8, sample size = 25 The 97.5th percentile of the standard normal is 1.96. and of the t-distribution with 24 degrees of freedom is 2.064 What is the UPPER limit of the 95% confidence interval for the population mean based on this sample? (Give your answer to 1 decimal place.) QUESTION 9 An analyst wishes to estimate the average height to within a margin of error of 3cm. A pilot study of a sample of 50 individuals found an average height of 1 73.5cm with a standard deviation of 15.8cm. What is the required sample size? (You may use the value 1.96 in your calculation, rather than the value from the t(n-1) distribution.) 2 NB: thesolution tom = 1.96 O isn = [136] 02 J; m